Issue 71

S. Eleonsky et alii, Fracture and Structural Integrity, 71 (2025) 246-262; DOI: 10.3221/IGF-ESIS.71.18

Contact dimple diameter 2 R 0 , mm

Pressure force P , kN

Impact energy E , J

Specimen

S_1 S_2 S_3 D_1 D_2 D_3

3.0 3.0 3.0

6.1 6.0 5.9 6.1 6.1 6.1

40 40 40

Table 1: Nomenclature of coupons and contact interaction parameters.

A process of static ball pressing in coupons S_1, S_2 and S_3 is accompanied by distinctive noise before reaching given force value P = 3.0 kN. This fact evidences pronounced crash of surface fibers of composite plate. Static dimple diameters for all coupons coincide within the measurement uncertainty and practically coincide with dynamic dimple diameters. Mutual location of contact dimple borders and probe hole counters is shown in Fig. 2. Fig. 2a depicts local coordinate system used ( y – axis coincides with the vertical symmetry axis of each individual probe hole). Through holes, essential for residual stress deriving, are of 2.0 mm diameter. Hole number increase corresponds to the drilling order.

Figure 2: Scheme of mutual location of contact dimple border and probe hole edge: (a) S_1, real image; (b) S_1, drawing; (c) S_2; (d) D_1; (e) D_2; (f) S_3, D_3.

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